Apparatus for expanding heatexpandable ores



March 28, 1967 A. E. WAGNER APPARATUS FOR EXPANDING HEAT-EXPANDABLE ORES 5 Sheets-Sheet l Filed June 29. 1964 INVENTOR. 42515275 4M/vf@ March 28, 1967 A. E. WAGNER 31,311,358

APPARATUS FOR EXPANDING HEAT-EXPANDABLE CRES 5 Sheets-Sheet 2 Filed June 29, 1964 INVENTOR. A55/27 i ///A/fe March 28, 1967 A. E. WAGNER APPARATUS FOR EXPANDING HEAT-EXPANDABLE ORES 5 Sheets-Sheet 5 Filed June 29. 1964 March 28, 1967 A. E. WAGNER APPARATUS FOR EXPANDING HEAT-EXPANDABLE ORES 5 Sheets-Sheet 4 Filed June 29, 1964 /a/m/ MZ March 28, 1967 A. E. WAGNER APPARATUS FOR EXPANDING HEAT-EXPANDABLE ORES 5 Sheets-Sheet 5 Filed June 29. 1964 [sw/Emme. 45567-5 ,MMA/5e ma; ,Ma

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United States Patent O 3,311,358 APPARATU FR EXPANElNG HEAT- EXPANDABLE @RES Albert E. YvJagner, Sunland, Calif., assigner to Aden Supplies, Inc., a corporation of Caifornia Fiied June 29, 1964, Ser. No. 378,819 19 Claims. (Cl. 263-21) The present invention relates to improvements in ore processing and heating apparatus, and, more particularly, to improvements in means for heating and expanding expandable ores.

Heretofore it has been known to process, heat, and expand ores, such as perlite, in plant assemblies including flame heated, tubular ovens which are made to rotate while in an inclined position. In such assemblies, the ore is fed from a storage into the upper end of the ovens while they are being rotated. The objective is to rotate the ovens at such a speed and angle that the ore particles upon reaching the lower open ends of the ovens are expanded a desired amount.

Unfortunately, the known ore processing and heat expension assembiies are characterized by problems which limit the efciency of ore expansion, require the assemblies to occupy extremely large Hoor areas, and materially increase the overall cost ofthe assemblies as well as the expanded ore products of the assemblies.

For example, in conventional ore expansion assemblies it is common to include a separate pre-heat stage between the ore storage and the ovens of the assembly. The preheat stage generally includes a large hopper for receiving ore from the storge and numerous heating elements for heating and partially expanding the ore, which is then fed by separate ducts into the ovens of the assembly. If such pre-heaters are sufficiently elaborate they permit the use of somewhat small and inexpensive ovens and furnace structures for expanding the ores. However, such pre-heaters themselves occupy an appreciable amount of space, require separate maintenance, and constitute fairly expensive components of the overall assemblies.

Further, in assemblies of the foregoing type, it is presently the practice to extend the tubular ovens through opposite open ends of the surrounding furnace structure and to support the exposed ends of the ovens for rotation within separate bearing assemblies. The ovens are heated by direct flames from burners within the furnace structure. Such an arrangement does not produce uniform longitudinal heating of the tubular ovens. Hence, ex-

andable ore articles assino throu h such an oven are P P s subjected to different temperatures along the oven, and are prevented from achieving the desired or complete expansion.

Moreover7 the direct coupling of the bearing supports to the ends of the heated ovens subjects the bearings to extremely high temperatures requiring either periodic servicing and replacement of the bearing or that special high temperature bearings may be employed. In either case, the expense involved is relatively great.

Another shortcoming of conventional assemblies of the foregoing type is that they fail to recover large quantities of lightweight expanded ore particles of extremely small size, commonly called fines The lines constitute a fine powder which can be used separately or in a mix, and their loss contributes significantly to the overall cost of operating an assembly.

In view of the foregoing, it is a general object of this invention to provide improved means for expanding heat expandable ores which overcomes the foregoing problems.

Another object of this invention is to provide an assembly for expanding heat-expandable ores wherein the oven of the assembly is arranged t-o be heated to a uniform temperatures along its length and insure even heating of the ore as it passes through the oven.

A further object of this invention is to provide an assembly for expanding heat'expandable ores including a bearing support for the rotatable ovens of the assembly which is effectively insulated from the flame-heated structure of the ovens.

Still another object of this invention is to provide an assembly for expanding heat-expandible ores including a novel, long-lasting and highly insulated, yet simple, bearing support and coupling arrangement allowing the oven of the assembly to be stationed and rotated entirely within the furnace structure of the assembly.

A still further object of this invention is to provide a coupling of the foregoing type which allows expansion and contraction of the oven with heating and cooling.

It is another object of this invention to provide an assembly for expanding heat-expandable ores which does not require a separate pre-heating hopper with heating elements.

It is a further object to provide an assembly for expanding heat-expandable ores including compact means for partially expanding the ore as it is being fed into the ovens of the assembly.

It is still another object of this invention to provide an assembly for expanding heat-expandable ores capable of collecting particles of the ores formerly lost with the exhaust of prior assemblies of a similar type.

It is a still further object of this invention to provide an assembly of the foregoing type wherein the size of the lightweight particles collected may be controlled.

The foregoing as well as other objects and advantages of this invention will be more fully understood from the following description taken in connection with the accompanying drawings which set forth by way of illustration and example a particular embodiment of this inven-tion.

In the drawings:

FIGURE 1 is an elevational view of the assembly for expanding expandable ores showing the arrangement of components for storing the crushed ore in a storage hopper and initially heating, expanding and recovering fines of the ore particles and heating and partially expanding the ore particles as they are fed into tilted rotary ovens for fully expanding the ore, showing the means for selectively collecting further lightweight expanded particles of the ore from the exhaust of the ovens, and showing means for collecting and bagging the expanded particles;

FIGURE la is a fragmentary sectional side view of the feed mechanism for selectively and controllably feeding the ore from the storage hopper;

FIGURE 2 is a sectional side view of the furnace structure seen in FIGURE 1 showing the internal construction of the furnace structure and the feed, discharge, and exhaust components associated with the furnace structure;

FIGURE 3 is the vertical section view taken along the line 3 3 in FIGURE 2 showing further detail of the inner construction of the furnace structure, the positions of the rotary ovens and the location of the burners for heating the same together with the manifolds for supplying fuel to the burners;

FIGURE 4 is a fragmentary front elevation View taken along the line 4 4 in FIGURE 2 showing the drive means for operating a number of rotary ovens;

FGURE 5 is an expanded sectional side elevation of the furnace structure with the central portion removed, showing in more detail the insulated support, coupling, and rotary drive components for an oven in the assembly;

FIGURE 5a is a fragmentary sectional view of the Coupling assembly taken along the line 5cl- 5a in FIG- URE 5;

FIGURE 5b is a fragmentary sectional view of the coupling assembly taken along the line SI1- 5b in FIG- URE 5;

FIGURE 6 is a sectional side elevation of the component for feeding expandable ore palticles into the ovens of the assembly and initially heating and partially expanding the particles as they fall under the force of gravity into the ovens;

FIGURE 7 is a sectional top view of the feed and initial heating and expansion component of FIGURE 6 along the line 7-7 in FIGURE 6;

FIGURE 8 is a top longitudinal sectional view taken along the line S-S in FIGURE l, showing details of the structure for collecting lightweight expanded ore particles from the exhaust of the ovens;

FIGURE 9 is a fragmentary sectional side view taken along the line 9 9 in FIGURE 3, showing a control means for thc -fuel supplied to the burners of FIGURE 3; and

FIGURE l() is a fragmentary sectional rear elevation taken along the line 10-10 in FIGURE 2, showing the rear ends of the rotary ovens of the assembly and the discharge and exhaust ports from the furnace structure.

In the ore expansion assembly illustrated in FIGURE 1, crushed, heat-expandable ore, such as perlite, stored in a storage hopper 1Q is fed at a controlled rate via a plurality of ore feeders 11 and conveyor belts 12 to and through a vertical `feed and initial expander 13 into a plurality of inclined rotating tubular ovens housed within a furnace structure 14. In the ovens, the ore is heated, expanded, and discharged for collection in a pit 15 and by a line recovery mechanism 16. The expanded ore in the pit 15 is drawn into a collection hopper 17 and bagged for storage by a suitable bagging and conveyor mechanism 1S.

More particularly, to feed the crushed ore fr'om the storage hopper 1() at a controlled rate, the feeders 11 are secured over openings in the lower end of the hopper and each include a paddle wheel-shaped rotor 19. The rotor 19 is coupled to a pulley 20 and rotated within the feeder 11 by a drive belt 21 on the shaft of a variable speed motor 22. The motor 22 is secured to the frame work 3 supporting the hopper 1t). As the rotor 19 turns within the feeder 11, the paddles or vanes of the rotor carry the crushed ore from the open end of the hopper through the lower end of the feeder where it falls by gravity onto the upper surface of a conveyor belt 12.

Each conveyor belt 12 is stationed below a feeder 11, passes around and between a pair of rollers 24 and 25, and is driven from a motor (not shown) coupled to one of the rollers. The roller 24 is fixed to the frame 23 while the roller 25 is fixed to the structure of the initial expander 13. Thence the ore dropping from the feeders 11 is carried by the conveyor belts into the upper end of the initial expander.

The initial expander 13 comprises an outer tubular member or chimney 26 extending upward from the upper forward end of the furnace structure 14. Stationed within the chimney 26 are a plurality of vertically extending feed tubes 27, one for each oven within the furnace structure 14. The upper end of each feed tube 27 passes through an opening 2S and receives one of the rollers which is coupled to opposite sides of the feed tube. The lower end of the feed tube 2'7 leads to the front end of its associated tubular oven. Extending inward from opposite sides of each feed tube 27 are a plurality of vertically spaced, downwardly inclined, opposing, and alternating deflection plates 29.

The crushed ore particles carried by the conveyor belts 12 into the upper ends of the feed tubes 27 alternately engage and slide upon the dellecting plates 29 back and forth within the feed tubes as they cascade downward into the ovens within the furnace structure 14. As the ore particles fall downward within the feed tubes 27 they are heated by hot gases passing upward through the chimney 26, For this purpose, the hot gases are developed within the furnace structure 14 and vented through openings 30 in the top of the furnace structure and through ducts 31 into the chimney 26 adjacent the upper edge of the furnace structure.

Thus, arranged, the initial expander 13 provides for initial heating and partial expansion of the ore particles prior to their final expansion within the tubular ovens of the assembly. This allows the tubular ovens to be of relatively short length and provides for a compact furnace structure. Moreover, the initial heating and expansion of the ore is provided by the initial expander 13 entirely within the feed tubes into the rotary ovens and does not occupy or require large amounts of door space or separate heating elements as is the case with conventional ore expansion assemblies employing separate preheat hoppers.

The furnace structure 14 for housing the rotary ovens is most clearly illustrated in FIGURES 2 and 3 and includes a base member 32 having upwardly extending side walls 33 at opposite sides of the furnace structure and an upwardly extending middle wall or partition 34 midway between side walls 33. The partition 34 together with the sidewalls 33 support upper arches 35 which together with the base 32 form a pair of furnace chambers 36 and 37. Within each chamber, the upper surface of the base 32 curves upward to a central ridge along the chamber such that each of the chambers 36 and 37 in cross-section, resemble an inverted heart having left and right side lobes.

Stationed at the front and rear of the chambers 36 and 37 are front and rear walls 38 and 40 for the furnace structure. The front wall 38 includes four holes 39, one to each side lobe of the chambers 36 and 37. The holes are located side by side and, as will be described, are each adapted to receive the open front end of a tubular oven for mounting within the furnace structure. Similar to the front wall 3S, the rear wall 40 includes four holes 41, one for each side lobe of the chambers 36 and 37. Each hole 41 is aligned with and corresponds to a different hole 39 in the front wall 38 and is adapted to receive the rear end of a tubular oven within the furnace structure. In addition to the hole 41, the rear wall 40 also includes a pair of exhaust ports 42, one for each chamber 36 and 37. The exhaust -ports open into the holes 41 through the upper side of the rear wall 40. In line with the exhaust ports 42 are a pair of discharge ports 43 extending from the holes 41 through the lower side of the rear wall 4t).

The foregoing elements of the furnace structure 14 are composed of refractory material such as lire brick and are held together by metal plates 45 extending along the bottom, right and left sides, and front and rear of the furnace structure. T he plates 45 are secured together by a plurality of cross-connecting channel-shaped tie bars 46 which also extend along the front and rear ends and right and left sides of the furnace structure along the outside of the plates 45. The channel shape of the tie bars allows passage of air adjacent the plates 45 to assist in dissipating heat from the furnace structure 14.

To position the furnace structure 14 at the desired angle of tilt, it is preferable to support it on an axis located substantially under the middle portion of the structure so that the weight -on one end of the furnace beyond the tilting axis substantially counter-balances the weight of the furnace on the other side of the axis. For this purpose, and referring to FIGURES 2 and 3, bottom channels 46 are provided along the under side of the furnace structure 14. The channels 46 carry half-round sockets 47 midway along the furnace structure. Stationed opposite the sockets 47 are half-round sockets 48 supported on mounting blocks 49 atop a frame 50 stationed over the ground beneath the furnace structure. Passing between the half-round sockets 47 and 48 is a support pipe 51.

The pipe 51 is preferably xed to the half-round sockets 47 and rotates with the furnace structure within the sockets 48 over the frame 50. A stop member 52 extends upwardly from the rear of the frame 50 to serve as a limit stop to limit the angle through which the furnace structure can be tilted.

For adjusting the tilt angle of the furnace structure, manual or power means may be employed. In the example shown, a turn buckle 53 is used for this purpose and is positioned with its ends pivotally attached to the frame 5t) and to the bottom of the support furnace structure 14. In this manner, the furnace chambers 36 and 37 may be tilted to any desired angle to adjust the incline of the tubular ovens supported within the chambers.

The means for supporting the ovens within the furnace chambers are most clearly illustrated in FIGURES 2, 5,

5a and 5b. The tubular ovens, represented by the numerals 54, are of a hollow, cylindrical shape having openings at the ends thereof. In the preferred embodiment these openings are in the ends of the ovens which extend into the aligned front and rear holes 39 and 41 in the chambers 36 and 37. The ends of each oven are supported for rotation within the holes by front and rear coupling mechanisms 55 and 56 respectively. Briefly, the coupling mechanisms 55 and 56 extend through the front and rear holes 39 and 41 into the furnace chambers and are coupled to opposite ends of the ovens to support a pair of ovens side by side along each furnace chamber with the rear end of each oven opening into one of the discharge ports 43 and an exhaust port 42. Heat-expanded ore passing from the open ends of the ovens therefore drops through the discharge ports and hot fumes with any lightweight expanded ore particles travel upward from the ovens through the exhaust ports.

To this end, each front rotary coupling mechanism 55 includes a front plug 57 fixed within and over the front opening 39 in the furnace structure. The front plug 57 includes a relatively small central opening 58 and a pair of annular collars 59 and 60. The annular collar 59 is seated tightly within and around the inner surface of the hole 39 and includes a top hole 61 for receiving the lower end of a feed tube 27 passing between the front surface of the front wall 39 and the front end plate 45. The annular collar 69 lies within the collar 59 and includes an opening 62 in line with the opening 61 in the outer collar S9 and a slot 63 in its outer surface below the opening 58.

Stationed within the plug 57 is a front oven support member 64 having a plurality of openings 64 into the front end of the oven 54. The oven support member 64 includes an outer sleeve 65 extending around and fixed to the front end of the oven 54 with an annular collar 66 extending within a ring-shaped slot in the inner surface of the hole 39 adjacent the rear end of the collar 59. Around the front end of the sleeve 65 is an inwardly extending and rearwardly converging collar 67. The collar 67 is shaped such that its upper inner surface lies ab-ove the inner edge of the opening 62 and its lower surface lies adjacent the front end of the slot 63. The collar 67 thus acts as a guide for ore passing from the end of the feed tube 27, to `and through the slot 63 and openings 64 into the front end of the oven 54. The front oven support member 64 also includes a short, hollow shaft 68 extending forward through the central opening 5S in the front plug 57 to support the front end of the oven for rotation within the central opening in response to a turning of the shaft.

Secured to and around'the shaft 68 is a sleeve 69 carrying a spiral feed guide 74?. The -turning of the shaft 68 rotates the guide 70 to propel ore particles passing through the role 62 downward around the shaft 68 and through the slot 63 into the front end of the oven 54. In this regard, the rearward and upward incline of the collar 67 adjacent the slot 63 prevents the ore falling onto the lower inner surface of the sleeve 65 from escaping around the open end of the oven and into the furnace chamber since rotation of the sleeve causes the ore particles to travel upward along the incline into the open front end of the oven 54.

Fixed to and around the shaft 68 outside the furnace structure 14 is a first annular coupling member 7l having,J a plurality of forwardly extending spokes 72 each including a threaded hole 73. A plug 74 is seated within the open end of the shaft 68 to prevent the escape of ore through the shaft.

An insulator ring 75, preferably formed of transite, is coupled to the front end of the spokes 72 by a plurality of screws illustrated in cross section in FIGURE 5a at 76.

Secured to the front side of the insulator ring 75 is a second annular coupling member 77 having a plurality of rearwardly extending spokes 78 engaging the front surface of the insulator ring and coupled thereto by a plurality of screws 79.

Stationed within land extending through the central opening in the annular coupling member 77 is a hollow shaft 80. The hollow shaft 86 is adapted to rotate with the coupling member 77 and is surrounded by a pair of spaced ball bearing assemblies 81. The assemblies 81 are, in turn, supported by a support coupling 82 fixed to the outer surface `of a cross plate 83 extending between the ends of the side plates 45 for the furnace structure. A plug 84 is stationed within the outer end of the shaft 80 and includes a plurality of air ports 85.

From the foregoing, it is appreciated that the coupling mechanisms 55 provide means for supporting the front ends of the ovens 54 entirely within the chambers in the furnace structure and for feeding ore through the furnace struct-ure into the raised front ends of the ovens. Also, the portions of the coupling mechanisms 55 contacting the oven are heat-insulated and separated from the portions of the coupling mechanism including the bearing assemblies 81. Therefore, the heat of the oven 54 does not directly flow to or interfere in any way with the operation of the outer coupling and bearing support of the overall coupling mechanism 55. Further, the hollow tubular arrangement of the coupling mechanism together with the spoked nature of the annular coupling members 71 and 77 provides means for pumping cool air through the coupling mechanism around the bearing assemblies 81. In this regard, rotation of the spokes 72 -an-d 78 with the coupling mechanism draws cool air through the air ports 85 in the end of the shaft S0 past the bearing assemblies 81 and outward through the opening between the spokes to provide cooling for the bearing assemblies. Also, it is appreciated that the coupling for the front end of the oven 54 is slidable through the opening 58 in the plug 57 to -allow for expansion and contraction of the oven 54 with the heating and cooling thereof.

The rear coupling mechanisms 56 are similar to the front coupling mechanisms 55 and each include a rear plug 86 fixed within and over one of the rear openings 41 with a relatively small central opening 87 communicating with the rear vopening 41. Extending within the furnace chamber and through the opening 87 is a rear oven support member 88 having an outer sleeve 89 fixed to and extending around the rear end of the oven 54 to. support the rear end of the oven adjacent the forward end of one of the exhaust ports 42 and the discharge ports 43. The sleeve 89 includes a plurality of openings 90 leading to the exha-ust port 42 and the discharge port 43. Extending rearward from the sleeve portion 89 is a short hollow shaft 91. The shaft 91 extends through the central opening 87 in the plug S6 and supports an annular coupling member 92 similar to the coupling member 71 previously described. The remainder of the coupling assembly 56 is the same as the coupling mechanism 55 including an insulation ring 93 fixed to the rear of the annular coupling 92 and an annular coupling 94 secured l to the rear of the insulation ring 93. The annular coupling 94, in turn, is fixed to and around a hollow shaft supported by a pair of bearing assemblies 96. The assemblies 96 are coupled to a support frame 97 secured to a cross-connecting member 93 extending between side plates 45 of the furnace structure. An end plug 99 including air holes 100 is xed within the open end of the hollow tube 95.

The rear coupling mechanism Se' thus provides means for support for the rear end of the oven 54 for longitudinal expansion and contraction entirely within the furnace structure, provides heat insulation between the portions of the coupling contacting the heated oven 54 and the portion supported for rotation by the bearing assemblies 96, and provides for air-cooling of the bearings with rotation of the coupling mechanism.

To produce the desired rotation of the ovens 54, a sprocket 101 is fixed to and around each annular coupling member 77 'for the ovens 54. The sprockets 101 form integral parts of a rotary drive mechanism which also includes a variable speed motor 102 mounted on the side of the furnace structure 14 with its drive shaft extending to a gear box 163 having its output shaft coupled to a drive gear 104 in line with the sprockets 101. A continuous drive chain 105 passes around the drive gear 104, a pair of idler gears 106 and 107 and loops aro-und the sprockets 101 in the manner illustrated in FIGURE 4, namely, around the left hand sprocket over the top of the next sprocket, around the bottom of the following sprocket and over the top of the right hand sprocket and thence back to the drive gear 164.

The drive gear 104 is rotated in a counterclockwise direction by the motor 102. Hence, the sprockets 101 and the associated tubular oven 54 are rotated in the directions indicated by the arrows in FIGURE 4, to wit, the left hand oven of each pair of ovens is rotated in a counterclockwise direction while the right hand oven of each pair is rotated in a clockwise direction. This means that the ore is entering and passing along each left side oven rotates to and slides downward along the fourth quadrant of the oven while the ore in each right side oven rotates to and slides along the third quadrant of the oven. As will be discussed later, this is important to the uniform heating and complete expansion of the ore passing through the ovens.

The apparatus for heating the ovens is stationed above and along the outside of each pair of ovens and is adapted to establish downward extending flames along the sidewalls of the oven chambers. Preferably, the heating apparatus includes a number of longitudinally spaced refractory sleeves 108 stationed in generally vertical planes through the arc-hes 35 at opposite sides of the furnace chambers 36 and 37. The sleeves 103 are adapted to receive burner nozzles 169 coupled by flexible tubing 110 to a fuel supply assembly. The fuel supply assembly includes the pipe 51 which is coupled at one end to a fuel supply and capped at an opposite end. Separate fuel lines 111 and 112 extend from the left and right ends of the pipe 51 and are joined to each other above the upper surface of the furnace structure at 113. Preferably, the joint 113 is closed to isolate the lines 111 and 112 from each other. Two pair of closed end manifolds 111 and 112 coupled to the fuel lines 111 and 112, respectively, above the furnace structure extend along opposite sides of the chambers 36 and 37. The exible tubes 110 extend downward from the manifolds 111 and 112' to provide fuel for the nozzles 109.

The amount of fuel supplied to the nozzles 109 for the chambers 36 and 37 may be selectively regulated by a regulator 114 included within the pipe 51. The regulator 114 in its most basic form comprises a disc 115 supported on a rod 116 extending through a lower surface of the pipe 51 to provide a hand-grasping means for turning the disc to block and unblock flow of fuel to the fuel line 112 and hence to the nozzles 109 for the furnace chamber 36. In this manner, the amount of fuel and hence the temperature within the furnaces 36 and 37 may be selectively adjusted to provide for different degrees of expansion of the ore as it passes through the ovens in the respective furnace chambers.

For igniting the fuel from the nozzles, the sidewalls 33 are provided with openings 117. The openings 117 are sufficiently large to enable a torch to be inserted through them when the nozzles are to be lighted. Normally, the holes 117 are closed by blocks of refractory material 118 seated within the holes and including handles 119 providing a hand-grasping means for moving the blocks 118 into and out of the holes.

Once the nozzles 109 are ignited by a torch, ames pass from the nozzles downward along the sidewalls 33 of the chambers 36 and 37. By reason of the disposition ot the inner faces of the chambers providing an internal heart-shaped design, the ames swirl around the lower surfaces of the ovens and upward between and cornpletely around the ovens, as indicated by the arrows in FIGURE 3. The ames from the nozzles thus heat the lateral surfaces of the ovens from points immediately adjacent the nozzles around to and including the quadrants of the ovens containing the ore being expanded. Accordingly, equal oven surface areas are subjected to flames prior to engaging the ore. This leads to a uniform heating temperature along the entire surfaces of the ovens within the furnace structure and together with the rotation of the ovens in the indicated direction, has provided a substantial and unexpected improvement in the quality and percentage of ore particles expanded in the ovens of the present invention.

By way of review, expandable ore is fed from the hopper 10 into the initial expansion means 13 where it passes downward through separate feed tubes 27 and is heated by hot air exhausted from the furnaces 36 and 37 through openings 30 and the ducts 31 leading to the chimney 26 of the initial expander. In the initial expander 13, the ore is partially expanded as it travels directly into and through the coupling mechanism 55 for each oven and into the front end of the ovens 54. Once in the ovens 54, the ore rotates with the ovens and lies in the previously mentioned quadrants where it is subjected to controlled heating as it travels downward under the force of gravity through the ovens. At the rear ends of the ovens 54, the ore, now expanded, drops through the discharge port 43 and an associated duct 44 into the pit 15. Exhaust gases from the oven travel upward through the exhaust port 42.

As previously indicated, it is common that some light weight expanded ore particles be carried upward with the exhaust from the ovens. Heretofore, such particles, commonly called tine have been lost. In the present invention, they are recovered, and may be recovered in a manner wherein the size of the recovered fine may be selectively controlled.

To accomplish this, the ore expansion assembly of the present invention includes the recovery apparatus 16. The recovery apparatus 16 comprises an exhaust chimney 117 xed to the top of the rear wall 40 of the furnace structure over the exhaust ports 42. The exhaust chimney 117 extends vertically from the furnace structure 14 upward to a rear opening 118 in the side of the recovery hopper 119. The recovery hopper 119 includes a generally tubular, relatively large upper portion 120 having a central opening 121 in its otherwise closed, upper surface, a front port 122 and a lower open end. The lower open end of the upper tubular portion 120 receives and is coupled to a funnel-shaped lower end portion 123 of the hopper 119. Series-connected ducts 124 and 125 are coupled to the lower open end of the funnelshaped portion 123 and lead downward into the pit 15.

Surrounding the front side port 122 is a hollow extension 126. The extension 126 is coupled to the hot air chimney 26 of the initial expander 13 to receive the hot air passing upward from the initial expander.

Within the recovery hopper 119 are stationed a pair of spiral-shaped deflection plates 127 and 128. The deflection plates are fixed to the upper inner surface of the upper tubular portion 126 and extend downward therefrom to a point above the lower end of the upper portion 120. rl^he deflection plate 127 has one end fixed to the left side of the opening 118 and spirals around and converges inwardly toward the central opening 121. Similarly, the deflection plate 128 is fixed to the right side of the opening 122 and spirals around and converges toward the central opening 121. The deflection plate 128 spirals within the spiral formed by the deflection plate 127 (see FIGURE 8).

Stationed within and passing through the central opening 122 is a vertically extending exhaust tube 129. The exhaust tube normally extends downward to a point adjacent the lower end of the deflection plates 127 and 128 and is secured within the opening 121 by a ring clamp 130 coupled to the upper surface of the hopper 119. By loosening the clamp 13G, the tube 129 may be slipped up and down within the opening 121 relative to the deflection plates. The position of the lower edge of the tube 129 determines the size of particles recovered by the recovery apparatus 16.

In particular, the hot exhaust gases from the ovens 54 travel upward through the exhaust chimney 117 and into the recovery hopper 119 through the opening 118. The hot exhaust gases carry the lightweight ore particles which are to be recovered. The gases, with the particles, contact the inner surface of the deflection plate 127 and are caused to travel in a spiral inwardly toward the central opening 121. As the exhaust gases and lightweight ore particles spiral inwardly, the particles lose momentum and slide downwardly along the inner surface of the deflection plate dropping into the funnel 123 and downward through the ducts 124 and 125 into the pit 15. The hot exhaust gases having spiralled inwardly along the inner surface of the deflection plate 127 then leave the lower surface of the deflection plate and are exhausted upward through the lower end of the tube 129.

lf the tube is even with or above the lower surface of the deflection plates, the exhaust gases simply exit from the lower surfaces of the deflection plates and travel upward into the tube 129 and through the central opening 121 where they are directed by a hood 131 clamped by a ring clamp 132 to the lower end of an exhaust pipe 133. The exhaust pipe may be vented to the atmosphere or to a suction means for drawing exhaust from the ore expansion assembly. However, if the tube 129 is positioned such that its lower end lies below the lower ends of the aforementioned deflection plates, the exhaust gases still carrying some lightweight expanded ore particles must travel downward from the lower edge of the deflection plates and then upward through the tube. During this process, further amounts of lightweight particles lose enough momentum to fall from the exhaust stream into the funnel 123 and hence to the pit 15. By selectively controlling the vertical position of the tube 129, it is therefore possible to provide a degree of control over the minimum and maximum size lightweight particles recovered from the exhaust.

In a similar manner, the hot gases escaping from the furnace chambers and passing upward through the chimney 26 are spiralled by the deflection plate 123 and travel upward through the tube 129 to the exhaust pipe 133. Any lightweight ore particles which have leaked into the furnace chambers and the fines developed in the feed tubes of the initial expander 13 are thereby recovered in the same manner as the particles in the exhaust from the ovens of the furnace structure. This insures that substantially all lightweight particles from the ovens are recovered and directed into the pit and that fines do not enter the ovens and impair their operation. It should be noted, however, that if it is desired to separate the 1@ lightweight particles from the heavier expanded ore discharged through the discharge port 43, that the duct may be disconnected from the duct 124 and separate bagging and removal means stationed under the duct 124 to separately recover the lightweight particles.

It should also be noted that any undesired moisture in the ore particles fed into the initial expander 13 is carried upward with the hot fumes in the chimney 26 and dissipated in the recovery apparatus.

With regard to the possible leakage of ore into the furnace chambers, it should be noted that the furnace structure of the present invention includes Separate means for preventing such occurrences. In particular, it has been found that as the heated ovens 54trotate within the furnace structure, a vacuum is developed at the lower surfaces of the furnace chambers which tends to draw ore from the feed path for the ovens into the furnace chambers. As previously described, such is prevented in the coupling mechanism 55 by the inwardly inclined collar 67 of the oven support 6ft. To insure that there is no leakage around the collar 67, however, the furnace structure further includes a plurality of holes 134 in the lower side of the front wall 3S of the furnace structure lleading through the lower side plate 56 into the front openings 39 below the front coupling mechanisms 55. The holes 134 serve to break and prevent the development of a vacuum within the furnace chambers and thereby insure that ore or lightweight expanded ore particles are not drawn from the ore feed or the oven into the furnace chambers. As previously mentioned, however, if any lightweight particles should be drawn into the furnace chambers, they are recovered by the recovery apparatus 16 previously described.

From the foregoing, it is appreciated that the present invention provides an ore expansion assembly which is more compact than prior similar assemblies including eparate pre-heat hoppers, provides for a maximum expansion of ores passing through its ovens, and recovers and collects not only the heavier expanded ore particles from the end of the ovens but also the lighter particles normally lost in the exhaust of ore assemblies of a similar nature.

In the foregoing specification, a preferred embodiment has been described. Modifications, of course, will occur to those skilled in the art without departing from the spirit of the invention. Therefore, it is intended that the present invention be limited in scope only by the following claims.

I claim:

1. An assembly for expanding crushed, heat-expandable ores, comprising:

a furnace structure including elements of refractory material defining an elongated furnace chamber having a pair of aligned front and rear vopenings in front and rear ends thereof, a side port from said chamber, a discharge port from said chamber through a lower side of said furnace structure adjacent said rear end of said chamber, and an exhaust port from said furnace chamber through an upper side of said furnace structure adjacent said rear end and communicating with said discharge port;

a pair of tubular ovens having openings at their ends;

rotary support means extending through said front and rear openings in said furnace chamber and coupled to opposite ends of said ovens for supporting sai-:l ovens side by side along said furnace chamber with a rear end of each oven opening into said discharge port and said exhaust port whereby crushed, heatexpandable ores expanded in said ovens and passing through said open rear ends drop through said discharge port and exhaust with any lightweight particles of said ores pass upward from said chamber Vthrough said exhaust port;

burner means in said furnace structure for establishing flames along opposite sides of said furnace chamber to heat lateral surfaces of said ovens;

rotary drive means coupled to said rotary support means for rotating said ovens in opposite directions relative to said burner means with the right side oven rotating in a clockwise direction and the left side oven rotating in a counterclockwise direction;

means adapted to support said furnace structure in a position wherein said ovens are tilted downward from the front toward the rear of said furnace structure;

initial expansion and supply means for crushed heatexpandable ores for delivering said ores into a front end of each oven and for partially expanding said material while entering said ovens including a first generally vertical chimney extending from said furnace structure, a hot air duct from said side port in said furnace structure to said chimney, and a generally vertical feed tube for each oven within said first chimney having an upper end adapted to receive ore through an opening in said irst chimney and a lower end leading to the front end of an oven;

and means for recovering said lightweight expanded ores in said exhaust including a second generally vertical chimney over said exhaust port, a recovery hopper comprising a relatively large vertical tubular member having an open bottom, a central exhaust opening in its top, a side port communicating with said second chimney, and a vertically extending spiral-shaped deflection plate extending downward from the top of said tubular member from one side of said port around and converging inward toward said exhaust opening.

2. An assembly for expanding crushed, heat-expandable ores, comprisinv:

a furnace structure including elements of refractory material defining a pair of separate elongated furnace chambers each having a pair of aligned front and rear openings in front and rear ends thereof, a side port from each chamber, a discharge port from said furnace chambers through a lower side of said furnace structure adjacent said rear end of said furnace chambers, and an exhaust port from said furnace chambers through an ripper side of said furnace structure adjacent said rear ends of said furnace chambers and communicating with said discharge port;

two pair of tubular ovens having openings at the ends thereof;

rotary support means extending through said front and rear openings in said furnace chambers and coupled to opposite ends of said ovens for supporting said pairs of ovens side by side along dilierent ones of said furnace chambers with a rear end of each oven opening into said discharge port and said exhaust port whereby crushed, heat-expandable ores expanded in said ovens passing through said rear open ends drop through said discharge port and exhaust with lightweight particles of said ores travel upward from said ovens through said exhaust port;

first and second burner means in generally vertical planes in said furnace structure for establishing flames along opposite sides of said furnace chambers to heat lateral surfaces of said pairs of ovens;

a supply line means for supplying burner fuel from the source to said first and second burner means;

means in said supply line for regulating the amount of fuel supplied to each burner means;

rotary drive means coupled to said rotary support means for rotating the ovens of each pair of ovens of each pair of ovens in opposite directions relative to said said first and second burner means such thc the right side oven of each pair rotates in a clockwise direction and the left side oven of each pair rotates in a counterclockwise direction;

means adapted to support said furnace structure in a position wherein said ovens are tilted downward from the front toward the rear of said furnace structure;

initial expansion and supply means for crushed heat expandable ores for feeding said ores into a front end of each oven and for partially expanding said ores while entering said ovens including a first generally vertical chimney extending from said furnace structure, .a hot air duct from each side port to said chimney and a generally vertical supply tube for each oven within said chimney having an upper end adapted to receive ore through an opening in said chimney and a lower end leading to the front end of an oven;

and means for recovering said lightweight particles in said exhaust including a second generally vertical chimney over said exhaust port, a recovery hopper comprising a relatively large vertically extending tubular member having an open bottom, a central exhaust opening in its top, and a side port communicating with said second chimney, a vertically extending spiral-shaped detiection plate extending from the top of said tubular member from one side of said side port around and converging inward toward said exhaust opening.

3. An assembly for expanding crushed, heat-expandable ores, comprising:

a furnace structure including elements of refractory materials defining a furnace chamber having front and rear openings in front `and rear ends thereof, a side port from said chamber, a discharge port from said chamber through a lower side of said furnace structure adjacent said rear end of said chamber, and an exhaust port from said chamber communieating with said discharge port;

a tubular oven having openings at the ends thereof;

rotary support means extending through said front and rear openings in said chamber and coupled to opposite ends of said oven for supporting said oven along said chamber with a rear end of said oven opening into said discharge port and said exhaust port;

burner means in said furnace structure for heating lateral surfaces of said oven;

rotary drive means coupled to said rotary support means for rotating said oven;

means adapted to support said furnace structure in a position wherein said oven is tilted downward from the front toward the rear of said furnace structure;

initial expansion land supply means for crushed, heatexpandable ores for delivering said ores into a front end of said oven and for partially expanding said ores while entering said oven including a first generally vertical chimney extending from said furnace structure, a hot air duct from said side port to said rst chimney and a generally vertical feed tube within said chimney having an upper end adapted to receive said ore through an opening in said first chimney and a lower end leading to the front end of said oven;

and means for recovering lightweight expanded ore particles passing with exhaust through said exhaust port in said furnace structure including a second generally vertical chimney over said exhaust port, a recovery hopper comprising a relatively large vertically extending tubular member having an open bottom, a central exhaust open in its top, and a side port communicating with said second chimney, and a vertically extending spiral-shaped deflection plate extending from the top of said tubular member from one side of said side port around and converging inward toward said exhaust opening.

4. The assembly of claim 3 including vacuum breaker 13 means comprising a hole through said furnace structure from a lower side of said chamber.

5. The assembly of claim 3 wherein said recovery hopper further includes a generally vertical exhaust-carrying tube stationed for sliding movement through said exhaust opening in said tubular member.

6. An assembly for expanding crushed, heat-expandable ores, comprising;

a furnace structure including eiements of refractory materials defining a furnace chamber having front and rear openings in front and rear ends thereof, a side port from said chamber, a discharge port from said chamber through a lower side of said furnace structure adjacent said rear end of said chamber, and an exhaust port from said chamber communicating with said discharge pon;

a tubular oven having `openings at the ends thereof;

rotary support means extending through said front and rear openings in said chamber and coupled to opposite ends of said oven for supporting said oven along said chamber with a rear end of said oven opening into said discharge port and said exhaust port;

burner means in said furnace structure for heating lateral surfaces of said oven;

rotary drive means coupled to said rotary support means for rotating said oven;

means adapted to support said furnace structure in a position wherein said oven is tilted downward from the front toward the rear of said furnace structure;

initial expansion and supply means for crushed, heatexpandable ore for delivering said ores into a front end of said oven and for partially expanding said ores while entering said oven including a rst generally vertical chimney extending from said furnace structure, a hot air duct from said side port to said rst chimney and a generally vertical feed tube within said chimney having an upper end adapted to receive said ores through an opening in said chimney and a lower end leading to the front end of said oven;

and means for recovering lightweight expanded ore particles carried by exhaust leaving said oven through said exhaust port including a second generally vertical chimney over said exhaust port and a recovery hopper comprising a relatively large vertically extending tubular member having an open bottom, a central exhaust opening in its top, a rst side port communicating with said second chimney, a second side port spaced around said tubuiar member from said rst side port, a first vertically extending, spiralshaped deflection plate extending from the top of said tubular member and from one side of said first side port around and converging inward toward said exhaust opening, and a second vertically extending spiral-shaped deection plate extending from the top of said tubular member and from an opposite side of said second port around and converging toward said exhaust opening, said second plate spiralling within said rst deection plate, and a generally vertical exhaust-carrying tube stationed for vertical sliding movement within said exhaust opening;

and means connecting said first chimney to said second port in said tubular member.

7. ln an assembly for expanding crushed, heat-expandable ores, the combination of:

a furnace structure including elements of refractoy material defining a furnace chamber having front and rear openings in front and rear ends thereof, a discharge port from said chamber through a lower side of said furnace structure adjacent said rear end of said chamber, and an exhaust port from said chamber communicating with said discharge port;

a tubular oven having openings at the ends thereof;

front and rear rotary support means extending through said front and rear openings in said furnace cham- CJI ifi ber and coupled to opposite ends of said oven for supporting said oven along said furnace chamber with an open rear end of said oven opening into said exhaust port and said discharge port whereby crushed, heat-expandable ore expands in said oven and passing through said open rear end drops through said discharge port and exhaust with any lightweight ore particles travel upward from said oven through said exhaust port, said front rotary support means comprising a front plug xed within and over said front opening in said furnace structure and having an opening communicating with said front opening and a top port for receiving said ore, a front oven support member fixed to the frontend of said oven within said chamber and including a feed opening into said front end of said oven and a short shaft extending forward through said opening in said front plug to support the front end of said oven for rotation within said chamber in response to a turning of said short shaft, and a rst insulator fixably coupled to said short shaft outside said furnace structure, and said rear rotary support means comprising a rear plug fixed within and over said rear opening having an opening communicating with said rear opening, a rear oven support member fixed to the rear end of said oven within said chamber and including a plurality of openings communicating with said exhaust port and said discharge port and a short shaft extending rearward through said opening in said rear plug to support the rear end of said oven for rotation within said chamber, and a second insulator xably coupled to said shaft of said rear support member outside said furnace structure;

burner means in said furnace structure for heating lateral surfaces of said oven;

means adapted to support said furnace structure in a position wherein said oven is tilted downward from the front toward the rear of said furnace structure;

and rotary drive means coupled to one of said insulators for rotating said oven.

8. In an assembly for expanding crushed, heat-expandable ores, the combination of:

a furnace structure including elements of refractory material defining a furnace chamber having front and rear openings in the front and rear ends thereof, and a discharge port from said furnace through a lower side of said furnace structure adjacent said rear end of said chamber;

a tubular oven having openings at the ends thereof;

front and rear rotary support means extending through said front and rear openings in said chamber and coupled to opposite ends of said oven for supporting said oven along said chamber with a rear end of said oven opening into said discharge port, said front rotary support means including a front plug xed within and over said front opening and having a central opening communicating with said front opening and a top feed port for receiving heat-expandable ores, a front oven support member fixed to the front end of said oven within said chamber and including a feed opening into said front end of said oven and a rst short shaft extending forward through said central opening in said front plug to support said oven for rotation within said chamber in response to a turning of said first shaft, a rst annular coupling member fixed to the end of said rst shaft outside said furnace structure, a first insulator fixed to said first coupling member, a second annular coupling member including a plurality of generally horizontal spokes around the opening in said second coupling member and extending toward and xed to said first insulator, a first hollow shaft xed within and extending forward through said opening in said second annular coupling member, and a rst bearing support around said first i hollow shaft, and said second rotary support means including a rear plug within and over said rear opening and having a central Opening communicating with said rear opening, a rear oven support member fixed to the rear end of said oven within said chamber and including a side opening to said discharge port and a second short shaft extending rearward through said opening in said rear plug to support said oven for rotation within said chamber, a third annular coupling means fixed to the end of said second short shaft outside the furnace structure, a second insulator fixed to said third coupling means, a fourth annular coupling member including a plurality of generally horizontal spokes around the opening of said fourth coupling member extending toward and fixed to said second insulator, a second hollow shaft fixed within and extending rearward from said opening in said fourth annular coupling member, and a second bearing support around said second hollow shaft;

a rotary drive means;

a burner means in said furnace structure the lateral surfaces of said oven;

means for coupling a rotary support means to said rotary drive to rotate said oven in response to operation of said drive means such that rotation of said spokes draws air through said hollow shafts to cool said bearing means;

and means for feeding said ore into said feed port.

9. The combination of claim 8 including means for guiding said ore from said feed port in said front plug through said feed opening in said front oven support member into said oven.

10. The combination of claim 9 wherein said guide means includes a spiral feed guide around said first short shaft.

1l. ln an assembly for expanding crushed, heatexpandable ores, the combination of:

a furnace structure including elements of refractory material defining a furnace chamber having front and rear openings in the front and rear ends thereof, a discharge port from said furnace through a lower side of said furnace structure adjacent said rear end of said chamber, and an exhaust port from said chamber communicating with said discharge port;

a tubular oven having openings at the ends thereof;

front and rear rotary support means extending through said front and rear openings in said chamber and coupled to opposite ends of said oven for supporting said oven along said chamber with a rear end of said oven opening into said discharge and exhaust ports, said front rotary support means including a front plug fixed within and over said front opening and having a relatively small central opening communicating with said front opening and a top feed port for receiving first heat-expandable materials, a front -oven support member comprising an outer sleeve having a rear end fixed to the front end of said oven and an inwardly extending and rearwardly converging collar at a front end of said sleeve, a first short shaft extending forward through said central opening in said front plug to support said oven for rotation within said chamber in response to a turning of said shaft, and a plurality of feed openings around said shaft into said front end of said oven, a first annular coupling member fixed to the end of said first short shaft outside said furnace structure, a first insulator fixed to said first coupling member, a second annular coupling member including a plurality of generally horizontal spokes around the opening in said second coupling member extending toward and fixed to said first insulator, a first hollow shaft fixed within and extending forward through said opening in said second annular coupling member, and a first bearing support assembly around said first hollow shaft, and said Second rotary support means including a rear plug within and over said rear opening and having a relafor heating CJD Cai

p en V tively small central opening communicating with said rear opening, a rear oven support member fixed to the rear end of said Oven within said chamber and including a plurality of said openings to said discharge :ind exhaust ports and a second short shaft extending rearward through said onening in said rear plug to support said oven for rctation within said chamber, a third annular coupling means fixed to the end of said second short shaft outside the furnace structure, a second insulator fixed to said third coupling means, a fourth annular coupling member including a plurality of generally horizontal spokes around the opening of said fourth coupling member extending toward and fixed to said second insulator, a second hollow shaft fixed within and extending rearward from said opening in said fourth annular coupling member, and a second bearing support assembly around said second hollow shaft;

a rotary drive means;

a burner means in said furnace structure for heating the lateral surface of Said oven;

means for coupling a rotary support means to said rotary drive to rotate said oven in response to operation of said drive means such that rotation of said spokes draws air through said hollow shaft to cool said bearing means;

and means for feeding said ore into said feed port.

12. The combination of claim 1l including a spiral feed guide around said first short shaft for guiding said ore from said top feed port in said front plug through said feed openings in said front oven support member with rotation of said oven.

13. An assembly for expanding crushed, heat-expandable ores, comprising:

a furnace structure including elements of refractory materials defining a furnace chamber having front and rear openings in front and rear ends thereof, a side port from said chamber, a discharge port from said chamber through a lower side of said furnace structure adjacent said rear end of said chamber, and an exhaust port from said chamber communicating with said discharge port;

a tubular oven having openings at the ends thereof;

rotary support means extending through said front and rear openings in said chamber and coupled to opposite ends of said oven for supporting said oven along said chamber with a rear end of said oven opening into said discharge port and said exhaust port;

burner means in said furnace structure for heating lateral surfaces of said oven;

rotary drive means coupled to said rotary support means for rotating said oven;

means adapted to support said furnace structure in a position wherein said oven is tilted downward from the front toward the rear of said furnace structure:

initial expansion and supply means for crushed, heatexpandable ores for delivering said ores into a front end of said oven and for partially expanding said ores while entering said oven including a first generally vertical chimney extending from said furnace structure, a hot air duct from said side port to said first chimney and a generally vertical feed tube within said chimney having an upper end adapted to receive said ore through an opening in said first chimney and a lower end leading to the front end of said oven;

means for recovering lightweight expanded ore particles passing with exhaust through said exhaust port in said furnace structure including a second generally vertical chimney over said exhaust port, a recovery hopper comprising a relatively large vertically extending tubular member having an open bottom, a central exhaust open in its top, and a side port communicating with said second chimney, and a vertically extending spiral-shapecl deflection plate extending from 14. In an assembly for expanding crushed heat-expandable ores, a combination of:

a furnace structure including elements of refractory material defining a furnace chamber having front and rear openings in front and rear ends thereof, and a discharge port adjacent said rear end;

a tubular oven having open ends;

front and rear rotary support means extending through said front and rear openings in said furnace chamber and coupled to opposite ends of said oven, said front rotary support means comprising a front plug fixed within and over said front opening in said furnace structure and having an opening communicating with said front opening, a front oven support member fixed to the front end of said oven within said chamber and including an ore feed opening into said front end of said oven and a first shaft extending forward through said opening in said front plug to support the front end of said oven for rotation within said chamber in response to a turning of said shaft, and a first insulator connected to said first shaft outside said furnace structure, and said rear rotary support means comprising a lrear plug fixed within and over said rear opening havino an opening communicating with said rear opening, a rear oven support member fixed to the rear end of said oven within said chamber and including an opening communicating with said discharge port from said furnace structure and a second shaft extending rearwardly through said opening in said rear plug to support said rear end of said oven for rotation within said chamber, and a second insulator connected to said second shaft outside said furnace structure;

burner means in said furnace structure for heating lateral surfaces of said oven; means adapted to support said furnace structure in a position wherein said oven is tilted downward from the front toward the rear of said furnace structure;

and rotary drive means coupled to one of said insulators for rotating said oven.

15. The combination of claim 14 further including third and fourth shafts connected to said first and second insulators outside said furnace structure and bearing units between said third and fourth shafts and said means supporting said furnace structure whereby said bearing units l permit rotation of said oven within said chamber and whereby said front and rear rotary support means heat insulate said bearing units from said furnace chamber.

16. The combination of claim l further including front and rear annular coupling members connecting said third and fourth shafts to said first and second insulators, respectively, said third and fourth shafts being tubular, said front and rear annular coupling members including a plurality of generally horizontal spokes extending rearward and forward from said front and rear coupling members, respectively, said third and fourth shafts being fixed within and extending forward and rearward through said front and rear annular coupling members, respectively, whereby a rotation of said oven produces a like rotation of said annular coupling members and whereby said spokes draw air through said tubular third and fourth shafts to cool said bearing units.

17. A combination of claim 14 wherein said front plug includes a top port for receiving heat expandable ore.

1S. A combination of claim 17 including means for guiding ore from said top port in said front plug through said feed opening in said front oven support member into said oven.

19. A furnace assembly for expanding crushed heatexpandable ore, comprising:

a furnace structure including elements of refractory material defining an open-ended, elongated furnace chamber having an inverted, generally heart-shaped cross section with communicating right and left side lobes;

first and second tubular ovens extending along and supported for rotary movement within said right and said left side lobes of said furnace chamber;

a plurality of generally vertical burner nozzles supported in said furnace structure above said first and said second ovens and spaced along opposite longitudinal side surfaces of said furnace chamber, said nozzles opening downward along said side surfaces to direct ames downwardly therealong to follow the heart-shaped contour of said chamber and to swirl upwardly between and around said ovens;

means for supporting said furnace structure in a position wherein said ovens are supported downward from the front toward the rear of said furnace structure;

means for feeding heat-expandable ore into a front end of each of said ovens;

and rotary drive means connected to said ovens for rotating said first and `second ovens in opposite directions whereby said heat-expandable ore travels downward along one of said ovens in a third quadrant thereof and downward along the other oven in a fourth quadrant thereof, whereby said fiames from said burner nozzles heat equal oven surfaces prior to being directed at the quadrants carrying said ore to insure a uniform heating of said ore within sa-id ovens.

References Cited hy the Examiner UNTED STATES PATENTS 658,832 10/1900 Danvin 55-461 X 1,270,307 6/1918 Leyes 263-34 1,419,131 6/1922 Foster 263-34 1,690,068 10/1928 Eckfeldt 263-34 2,047,064 7/1936 Gillette 263-29 X 2,638,181 5/1953 Gordon 55-412 X 2,807,453 9/1957 Pierce 263-21 FREDERCK L. MATTESON, I R., Primary Examiner. D. A. TAMBURRO, Assistant Examiner. 

1. AN ASSEMBLY FOR EXPANDING CRUSHED, HEAT-EXPANDABLE ORES, COMPRISING: A FURNACE STRUCTURE INCLUDING ELEMENTS OF REFRACTORY MATERIAL DEFINING AN ELONGATED FURANCE CHAMBER HAVING A PAIR OF ALIGNED FRONT AND REAR OPENINGS IN FRONT AND REAR ENDS THEREOF, A SIDE PORT FROM SAID CHAMBER, A DISCHARGE PORT FROM SAID CHAMBER THROUGH A LOWER SIDE OF SAID FURNACE STRUCTURE ADJACENT SAID REAR END OF SAID CHAMBER, AND AN EXHAUST PORT FROM SAID FURANCE CHAMBER THROUGH AN UPPER SIDE OF SAID FURNACE STRUCTURE ADJACENT SAID REAR END AND COMMUNICATING WITH SAID DISCHARGE PORT; A PAIR OF TUBULAR OVENS HAVING OPENINGS AT THEIR ENDS; ROTARY SUPPORT MEANS EXTENDING THROUGH SAID FRONT AND REAR OPENINGS IN SAID FURNACE CHAMBER AND COUPLED TO OPPOSITE ENDS OF SAID OVENS FOR SUPPORTING SAID OVENS SIDE BY SIDE ALONG SAID FURNACE CHAMBER WITH A REAR END OF EACH OVEN OPENING INTO SAID DISCHARGE PORT AND SAID EXHAUST PORT WHEREBY CRUSHED, HEATEXPANDABLE ORES EXPANDED IN SAID OVENS AND PASSING THROUGH SAID OPEN REAR ENDS DROP THROUGH SAID DISCHARGE PORT AND EXHAUST WITH ANY LIGHTWEIGHT PARTICLES OF SAID ORES PASS UPWARD FROM SAID CHAMBER THROUGH SAID EXHAUST PORT; BURNER MEANS IN SAID FURNACE STRUCTURE FOR ESTABLISHING FLAMES ALONG OPPOSITE SIDES OF SAID FURNACE CHAMBER TO HEAT LATERAL SURFACES OF SAID OVENS; ROTARY DRIVE MEANS COUPLED TO SAID ROTARY SUPPORT MEANS FOR ROTATING SAID OVENS IN OPPOSITE DIRECTIONS RELATIVE TO SAID BURNER MEANS WITH THE RIGHT SIDE OVEN ROTATING IN A CLOCKWISE DIRECTION AND THE LEFT SIDE OVEN ROTATING IN A COUNTERCLOCKWISE DIRECTION; MEANS ADAPTED TO SUPPORT SAID FURNACE STRUCTURE IN A POSITION WHEREIN SAID OVENS ARE TILTED DOWNWARD FROM THE FRONT TOWARD THE REAR OF SAID FURNACE STRUCTURE; INITIAL EXPANSION AND SUPPLY MEANS FOR CRUSHED HEATEXPANDABLE ORES FOR DELIVERING SAID ORES INTO A FRONT END OF EACH OVEN AND FOR PARTIALLY EXPANDING SAID MATERIAL WHILE ENTERING SAID OVENS INCLUDING A FIRST GENERALLY VERTICAL CHIMNEY EXTENDING FROM SAID FURNACE STRUCTURE, A HOT AIR DUCT FROM SAID SIDE PORT IN SAID FURNACE STRUCTURE TO SAID CHIMNEY, AND A GENERALLY VERTICAL FEED TUBE FOR EACH OVEN WITHIN SAID FIRST CHIMMNEY HAVING AN UPPER END ADAPTED TO RECEIVE ORE THROUGH AN OPENING IN SAID FIRST CHIMNEY AND A LOWER END LEADING TO THE FRONT END OF AN OVEN; AND MEANS FOR RECOVERING SAID LIGHTWEIGHT EXPANDED ORES IN SAID EXHAUST INCLUDING A SECOND GENERALLY VERTICAL CHIMNEY OVER SAID EXHAUST PORT, A RECOVERY HOPPER COMPRISING A RELATIVELY LARGE VERTICAL TUBULAR MEMBER HAVING AN OPEN BOTTOM, A CENTRAL EXHAUST OPENING IN ITS TOP, A SIDE PORT COMMUNICATING WITH SAID SECOND CHIMNEY, AND A VERTICALLY EXTENDING SPIRAL-SHAPED DEFLECTION PLATE EXTENDING DOWNWARD FROM THE TOP OF SAID TUBULAR MEMBER FROM ONE SIDE OF SAID PORT AROUND AND CONVERGING INWARD TOWARD SAID EXHAUST OPENING. 